The Keeling Curve presents a challenge to our society

Transcription

1 The Keeling Curve presents a challenge to our society Pieter Tans NOAA Earth System Research Laboratory Boulder, Colorado webinar Climate Central 5 January

2 CARBON DIOXIDE AND CLIMATE 2

3 Outline: The three most important well known facts about climate change: Human activities are responsible for the emissions of greenhouse gases (GHGs). The emissions will stay in the atmosphere and oceans for thousands of years. The role of GHGs in retaining heat is established physics. Can we bring net emissions down to zero? 3

4 GHG INCREASES ARE DUE ENTIRELY TO OUR OWN ACTIVITIES www. esrl.noaa.gov/gmd/ccgg/trends/ 4

5 GHG INCREASES ARE DUE ENTIRELY TO OUR OWN ACTIVITIES History of atmospheric carbon dioxide Mauna Loa 400 central Antarctica Antarctic coast enlarge this portion 5

6 GHG INCREASES ARE DUE ENTIRELY TO OUR OWN ACTIVITIES 6

7 GHG INCREASES ARE DUE ENTIRELY TO OUR OWN ACTIVITIES Gton C Cumulative fossil fuel emissions (Jan. 2010) 355 ± 25 (source: CDIAC) Observed atmospheric increase (Jan. 2010) 231 ± 10 (source: ESRL) our daily barrel from: Aleklett, A peek at peak oil 7

8 GHG INCREASES ARE DUE ENTIRELY TO OUR OWN ACTIVITIES Gton C Cumulative fossil fuel emissions (Jan. 2010) 355 ± 25 (source: CDIAC) Observed atmospheric increase (Jan. 2010) 231 ± 10 (source: ESRL) Observed ocean increase through ± 19 (Sabine et al., Science 2004) modeled oceans, extrapolated through to Jan mass balance: fossil fuel emissions = atmos increase + ocean increase + terrestrial biosphere P.Tans, Oceanography 22 (4), 26-35,

9 INCREASING HUMAN DOMINATION OF THE CARBON CYCLE Net annual flows into and out of the atmosphere, and the amount remaining in the atmosphere (expressed in billion metric tons of carbon per year) 9

10 INTO THE FAR FUTURE, THOUSANDS OF YEARS 10

11 INTO THE FAR FUTURE, THOUSANDS OF YEARS 11

12 INTO THE FAR FUTURE, THOUSANDS OF YEARS Total retained energy by enhanced CO 2 alone, , can raise the temperature of the upper 1000 m of the oceans by 12 deg.c Not considered: negative climate forcings (cooling) such as fine particles (haze, also called aerosols) resulting from human activities. Earth s observed heat budget (D. Murphy, JGR 2009): Excess retained heat by GHGs ~half of one solar radiation-year. 12% heating of oceans 21% increased IR radiation to space 18% offset by cooling from stratospheric aerosols (volcanoes) ~50% offset by residual cooling, mostly by human-caused aerosols 12

13 ENHANCEMENT OF THE GREENHOUSE EFFECT Climate forcing by long lived GHGs (Watt m -2 ) CO2 CH4 N2O F-12 F-11 minor TOTAL %solar % solar Annual Greenhouse Gas Index:

14 CLIMATE FEEDBACKS AND UNCERTAINTY water vapor (f 1 ) ΔF ΔT snow & ice melt (f 2 ) CH4 & CO2 from permafrost melt (f 3 ) 14

15 CLIMATE FEEDBACKS AND UNCERTAINTY (movie: The Deer Hunter) Alexander McDonald, adapted from Roe & Baker, Science

16 We have already committed the Earth to significant climate change. Climate change is just one aspect, and perhaps the clearest manifestation yet, of the still increasing dominance of human activities on our planet. Our increasing domination over the Earth brings with it the responsibility to protect it, for the sake of future generations. The expectation of never ending growth has been driving our economic system for the last several centuries, but now unintended externalities of resource use on a finite Earth are becoming apparent. Our overarching challenge is to create a socio-economic system that is shrinking its use of resources, while still providing jobs, food, shelter, education and health care for everyone. 16

17 Our predicament: To minimize the probability of catastrophic climate change emissions will have to be lowered at an aggressive pace. Net CO2 emissions have to go to zero or negative. Most emissions until now have come from the developed countries. Developing countries will likely cause most of the future emissions. We need a demonstration that development with very low emissions is a feasible option. 17

18 LARGE EMISSIONS REDUCTIONS WITHOUT ECONOMIC COLLAPSE oil price shocks 18 Source: CDIAC

19 Some things we can do Energy efficiency and conservation: Efficient light bulbs and appliances, thermostat settings in summer and winter, improve home insulation, turn off standby power, commute by bicycle or public transport. Recycle and compost as much as you can. Does your city have three-stream waste collection, recyclables, compost, and real waste? Buy electricity from renewable sources from your power company, consider installing solar photovoltaic panels and/or hot water. Vote with your dollars: Buy less meat, non-endangered fish, become more vegetarian, buy only fuel-efficient cars and appliances. Talk about the issue with your friends and neighbors. Take your money out of the too big to fail banks by using credit unions. Stop voting for political candidates who have not proven to be serious about the energy and climate issue, and let them know why you withhold your vote. Write letters to your newspaper, call in to a local radio program. Join the movement to get (corporate) money out of politics. Insist (if necessary) that your local schools spend more time on our impact on the environment, and how we could decrease our footprint. 19

20 Some reading material: Summary for Policy Makers (and everything else IPCC), download from Andrew Weaver: Generation Us, The Challenge of Global Warming, 2012, Raven Books. (brief, clear, including broad social implications) Spencer Waert: The Discovery of Global Warming, updated 2008 Also web site (Waert is a historian of physics. This book is more detailed. How mankind s influence on climate slowly dawned on scientists) Naomi Oreskes and Erik Conway: Merchants of Doubt, 2011, Bloombury Press (Amazing story, how a small group of scientists, helped by corporations, has been very successful in obscuring the truth, from tobacco smoke to global warming) Bernard Lietaer and Stephen Belgin: New Money for a New World, 2012, Qiterra Press. (An eye opener, alternative ways to set up our monetary system that may be more suitable for a no-growth economy) 20

21 A few reserve slides about the greenhouse effect 21

22 THE GREENHOUSE EFFECT What is infrared radiation? Nature, 2008 cooler warmer 22

23 THE GREENHOUSE EFFECT equilibrium average surface temperature -18 o C (-1 o F) 23

24 THE GREENHOUSE EFFECT equilibrium average surface temperature 30 o C (86 o F) 24

25 THE GREENHOUSE EFFECT Earth s outgoing infrared radiation spectrum (clear skies) over the Sahara desert as measured by Nimbus 4 satellite IR window regions INTENSITY H2O CO2 O3 CH4-70 C H2O 25 Hanel, JGR 1972